PORTLAND, Ore. — Portland’s police chief cautioned the public Sunday to reserve judgment after a video purportedly showing several officers fatally firing on a carjacking suspect at a homeless shelter made its way online.

Chief Danielle Outlaw said in a statement that she was aware of a video taken of the incident and posted on the internet, and asked the public to “please be reminded that deadly force investigations are extremely complex and take time.”

While responding to a report of a crash Saturday night, Portland officers learned that a car involved had been stolen in a carjacking earlier in the day, said police spokesman Sgt. Chris Burley.

Police found the man they believed to be the driver inside the nearby Cityteam Ministries Portland Shelter in southeast Portland. Officers received reports the man might be armed, Burley said.

But he said it has not yet been determined if he had a weapon at the time of the shooting, The Oregonian/OregonLive reported.

Police did not say what prompted officers to shoot.

“As officers contacted the adult male suspect, shots were fired,” police said in a statement. “Officers immediately requested emergency medical personnel respond to the scene.”

The suspect was pronounced dead at the scene.

No officers or bystanders were injured.

A few witnesses to the shooting told the newspaper that police were justified in taking lethal action. They said the man had gone into the shelter and was slashing and stabbing himself with a knife before lunging at officers.

“We were all scared for our lives,” said Morgan Thomas Pickering, of Portland. He said the scene was “horrific” and the man was acting erratically.